Smoke clears, breathing troubles may not

Those who suffer from respiratory ailments could still face troubles

The wildfire in northern Minnesota continues to burn, but its effect on Chicago air quality has diminished for now. (Clint Austin, McClatchy-Tribune)

Smoke from a wildfire in far northern Minnesota had largely dissipated in the Chicago area Wednesday but problems could linger for people with respiratory ailments.

"It's a difficult situation," said Dr. Joseph Leija, an allergist who collects the daily pollen and mold counts for the Chicago area. "With a heavy mold count and the smoke, the amount of oxygen in the air is diminished."

Conditions aren't in place for a return of the smoke Thursday, said WGN-TV meteorologist Tom Skilling.

Stable weather conditions and a breeze blew smoke over Lake Michigan and into the area Tuesday, but Thursday's forecast calls for unstable conditions, so if the smoke travels this far south it will probably be in western Illinois and Iowa, Skilling said.

Meanwhile airborne mold reached nearly 50,000 parts per cubic meter Tuesday, though the smoke made it difficult to conduct the count, said Leija, of Gottlieb Memorial Hospital in Melrose Park.

Decreased oxygen due to high particulate matter can lead even healthy people to tire easily. People with respiratory or cardiac illnesses tend to experience more serious symptoms, including weakness, fatigue, dizziness and headaches. They also may have a hard time recovering even though the air has cleared, Leija said.

Due to the poor air quality, the Illinois Environmental Protection Agency designated Wednesday an Air Pollution Action Day for Cook, DuPage, Grundy, Kane, Kendall, Lake, McHenry and Will counties. The classification is issued when air quality over a large area has reached or is expected to reach the level coded orange on the U.S. EPA's Air Quality Index for multiple days.

An orange code signifies that the air is unhealthy for sensitive groups, and the EPA advises that "people with heart or lung disease, older adults, and children should reduce prolonged or heavy exertion."

At last report, the wildfire in the Boundary Waters Canoe Area Wilderness had consumed more than 100,000 acres. The fire started Aug. 18 after a lightning strike, the U.S. Forest Service said, and smoke carried by northerly winds arrived in northern Illinois Tuesday morning.

As of Wednesday morning, a northwest wind was still gusting through the area of the fire at about 20 mph, but it was forecast to shift to the west and slow to about 5 mph by Thursday, according to the National Weather Service.

Residents could still smell traces of smoke Wednesday, and with the fire continuing to rage smoke could return, according to Rose Sengenberger, a meteorologist in the weather service's Romeoville office.

"It all depends on the situation" in Minnesota, Sengenberger said. "I wouldn't rule it out."

Leija fielded calls Tuesday from several ailing patients who wanted to know what to do, he said.

"For many people," he said "the only thing I can say is to stay inside with the air conditioning on."